Implement support for origin-TopLeft render targets. Note that the default behaviour remains the same:  textures default to origin-TopLeft, render targets default to origin-BottomLeft, and backend textures default to origin-BottomLeft. However, the caller can override the default by setting fOrigin in GrTextureDesc, GrBackendTextureDesc or GrBackendRenderTargetDesc.

Review URL: https://codereview.appspot.com/7230049

git-svn-id: http://skia.googlecode.com/svn/trunk@7594 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index dbc779f..7657813 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -295,6 +295,7 @@
             desc.fWidth = SkScalarRound(win->width());
             desc.fHeight = SkScalarRound(win->height());
             desc.fConfig = kSkia8888_PM_GrPixelConfig;
+            desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
             GR_GL_GetIntegerv(fCurIntf, GR_GL_SAMPLES, &desc.fSampleCnt);
             GR_GL_GetIntegerv(fCurIntf, GR_GL_STENCIL_BITS, &desc.fStencilBits);
             GrGLint buffer;